The primary goal for IRV is improved oxygenation by forcing inspiratory time to be greater than expiratory time (example: inhale is 3 seconds and exhalation is 1 second, a 3:1 I:E ratio) increasing the mean airway pressure and potentially improving oxygenation.
This may be due to the fact that IRV is not considered as a mode early enough once ARDS is diagnosed.
In a multicenter, randomized trial that compared PC-IRV to VC-IRV in patients with acute respiratory distress syndrome, the type of IRV did not affect mortality.
[13] The shorter expiratory time during IRV increases the risk of auto-PEEP and its associated development of problems (e.g. pulmonary barotrauma, hypotension).
In a study of 14 patients undergoing mechanical ventilation with PC-IRV, the incidence of pneumothorax was 29 percent despite the lack of measurable auto-PEEP.